Hello, I have a 2003 Disco with about 81k miles. Took an out of town trip and the service engine soon light came on. It went off after about 50 miles (maybe?). I noticed it was no longer on after I had restarted the engine a few times going between a couple short stops at my destination. The SES light never came back on the rest of the trip and has stayed that way so far.

I went ahead and went to Auto Zone to see if any codes could be read. They came up with P0134 and P0171 which was O2 sensor and bank 1 lean (if I recall correctly). The guy thought maybe it was related to the air filter. I took a look at it and it does appear that it needs to be replaced. They didn't have an air filter in stock anyways (any recommendations on what to use here?)

Is there anything for me to be concerned about? I forgot to see if they could clear the codes, so I'm sure I'll have to go back and ask if they can do that for me.

Also, would gas mileage be related? I've noticed since owning the Disco (had for about 6 months now), the city mpg is usually in the 12.5 to 13 range...on the highway, 14 mpg was what I averaged on the last trip.I went 65 mph on the first part of the trip and 75 mph on the return part...no difference in gas mileage... Is this typical? I've had the LR fuel conditioner added already at 75k miles...I've used Mobil 1 oil 10W30 as well. Let me know if you have any clues or if I am seeing typical results. I was just a little surprised that there wasn't much difference between my city and highway mileage.

Thanks for all your help.

 

Yeah that's basically typical for gas mileage. I'm not sure about your codes, but I'm sure Discomike or Spike will be in here, they know a lot more than I do. As far as your air filter, stick with the OEM paper ones, you can get it online at atlanticbritish.com. Don't get a K&N Air Filter, it will ruin your MAF, and you won't see a power gain using it anyway. Just to clarify, their oil filters are great, but stay away from the air filter.

 

Get a good factory filter in the truck, clear the codes and see if anything comes back.
Has the truck been tuned and what octane gas are you running?

 

Thanks all. I was told by the LR dealership that the maintenance was up to date (including 60k mile service). I've always used the premium fuel (91 octane).

Do you have to have the OBDII scanner to clear the codes?

Since the SES light went off, does that mean the codes are inactive then?